Objective To discuss clinical diagnosis and treatment of multiple endocrine neoplasia ( MEN) 2A,and report the mutation of RET proto-oncogene in a pedigree of three patients with MEN 2A. Methods Bilateral adrenalectom...Objective To discuss clinical diagnosis and treatment of multiple endocrine neoplasia ( MEN) 2A,and report the mutation of RET proto-oncogene in a pedigree of three patients with MEN 2A. Methods Bilateral adrenalectomy was performed on two of the three展开更多
OBJECTIVE: To report the clinical characteristics, biochemical profiles, diagnosis and treatment of one Chinese pedigree with glucocorticoid-remediable aldosteronism (GRA) and to study its molecular mechanism. METHODS...OBJECTIVE: To report the clinical characteristics, biochemical profiles, diagnosis and treatment of one Chinese pedigree with glucocorticoid-remediable aldosteronism (GRA) and to study its molecular mechanism. METHODS: Plasma and urinary aldosterone, cortisol and plasma renin activities were dynamically tested and diagnostic therapy with dexamethasone was undergone in 3 affected subjects. Long-distance PCR as well as DNA sequencing were applied to detect the fusion gene in this pedigree. RESULTS: In this GRA pedigree, there were 4 affected subjects who had hypertension, hypokalemia and low basic and provoked renin activity. Three patients were given dexamethasone treatment, and had a significant decrease in plasma aldosterone concentrations (PACs) (from 192 +/- 9 ng/L to 87 +/- 7ng/L, P展开更多
The mutation rate used in the previous analyses of pig evolution and demographics was cursory and hence invited potential bias in inferring evolutionary history.Herein,we estimated the de novo mutation rate of pigs as...The mutation rate used in the previous analyses of pig evolution and demographics was cursory and hence invited potential bias in inferring evolutionary history.Herein,we estimated the de novo mutation rate of pigs as 3.6×10-9 per base per generation using high-quality whole-genome sequencing data from nine individuals in a three-generation pedigree through stringent filtering and validation.Using this mutation rate,we re-investigated the evolutionary history of pigs.The estimated divergence time of~10 kiloyears ago(KYA)between European wild and domesticated pigs was consistent with the domestication time of European pigs based on archaeological evidence.However,other divergence events inferred here were not as ancient as previously described.Our estimates suggest that Sus speciation occurred~1.36 million years ago(MYA);European wild pigs split from Asian wild pigs only~219 KYA;and south and north Chinese wild pigs split~25 KYA.Meanwhile,our results showed that the most recent divergence event between Chinese wild and domesticated pigs occurred in the Hetao Plain,northern China,approximately 20 KYA,supporting the possibly independent domestication in northern China along the middle Yellow River.We also found that the maximum effective population size of pigs was~6 times larger than estimated before.An archaic migration from other Sus species originating~2 MYA to European pigs was detected during western colonization of pigs,which may affect the accuracy of previous demographic inference.Our de novo mutation rate estimation and its consequences for demographic history inference reasonably provide a new vision regarding the evolutionary history of pigs.展开更多
Objective To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy(HCM)focusing on the cardiac troponic C gene TNNC1 c.G175C mutation.Methods All family members of a Chinese pe...Objective To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy(HCM)focusing on the cardiac troponic C gene TNNC1 c.G175C mutation.Methods All family members of a Chinese pedigree with hypertrophic cardiomyopathy admitted in Third People’s Hospital of Qingdao展开更多
To report a new screening method for mitochondrial DNA 1555A→G mutation and the results of genotype analysis in 19 maternal inherited deafness pedigrees. Method Five hundred and forty-six non-syndromic neuro-sensory ...To report a new screening method for mitochondrial DNA 1555A→G mutation and the results of genotype analysis in 19 maternal inherited deafness pedigrees. Method Five hundred and forty-six non-syndromic neuro-sensory hearing loss patients were tested for 1555A→G mutation using a new compact testing kit, which allows clear distinction between wild type and 1555 A→G mutated mtDNAs. Results Nineteen subjects among the 546 patients (3.48%) were found to carry mtDNA A1555G mutation. The results were confirmed by sequencing in an ABI 3100 Avant sequencer. Conclusions Maternal inherited deafness families are a frequently seen in outpatient group. The detection of mtDNA 1555 A→G mutation with a low cost, ready to use detection kit is needed and suitable in China for large scale screening and preventive testing before usage of aminoglycoside antibiotics.展开更多
Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-di...Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-differentiable or explicit mathematical descriptions do not exist. Recently, evolutionary algorithms are gaining popularity for DOPs as they can be used as robust alternatives when the deterministic techniques are invalid. In this article, a technology named ranking-based mutation operator(RMO) is presented to enhance the previous differential evolution(DE) algorithms to solve DOPs using control vector parameterization. In the RMO, better individuals have higher probabilities to produce offspring, which is helpful for the performance enhancement of DE algorithms. Three DE-RMO algorithms are designed by incorporating the RMO. The three DE-RMO algorithms and their three original DE algorithms are applied to solve four constrained DOPs from the literature. Our simulation results indicate that DE-RMO algorithms exhibit better performance than previous non-ranking DE algorithms and other four evolutionary algorithms.展开更多
A dynamic genetic algorithms based on numeric encoding is proposed and its application in system identification is discussed. Simulation shows that the introduction of both numeric encoding and dynamic mutation can ef...A dynamic genetic algorithms based on numeric encoding is proposed and its application in system identification is discussed. Simulation shows that the introduction of both numeric encoding and dynamic mutation can effectively improve the accuracy and speed of searching for the optimum. It also show that the improved Genetic algorithm can identify time delay and parameters of the plant at the same time and converge to globle optimization.展开更多
The present study examined 58 members of a Kallmann syndrome family and investigated whether there are fibroblast growth factor receptor 1 (FGFR1) gene mutations in this family. Genomic DNA from the proband and fami...The present study examined 58 members of a Kallmann syndrome family and investigated whether there are fibroblast growth factor receptor 1 (FGFR1) gene mutations in this family. Genomic DNA from the proband and family members was subjected to PCR to amplify 18 exons of FGFR1, and the amplified products were sequenced to identify potential mutations. MRI of the olfactory bulb region was performed on suspected subjects. The patient and his father were diagnosed with Kallmann syndrome. A polymorphic site was found at 39542, with the proband and his parents being heterozygous (guanine + cytosine). However, healthy controls and the other members of this family were homozygous for guanine at this position.展开更多
Short tandem repeats on the Y chromosome(Y-STRs),characterized by paternal inheritance,are valuable in forensic practice.Notably,the potential application of Y-STRs in pedigrees should be drawn upon,especially in Chin...Short tandem repeats on the Y chromosome(Y-STRs),characterized by paternal inheritance,are valuable in forensic practice.Notably,the potential application of Y-STRs in pedigrees should be drawn upon,especially in China’s surname-concentrated natural villages.The study focused on 50 Y-STRs,including 13 rapidly mutating(RM)Y-STRs that largely constitute the current Y-STR commercial kits,and determined the differences in these Y-STRs between branches in a large pedigree and the discriminatory power of these haplotypes in different units for male relatives.As indicated in the results,14 inconsistencies were observed at 9 Y-STRs between 10 father-son pairs.In addition,these 50 Y-STR haplotypes discriminated 10 out of 47 father-son pairs,106 of 148 cousin pairs,70 of 119 uncle-nephew pairs,17 of 39 brother pairs,and 14 out of 33 grandfather-grandson pairs in a large pedigree.The RM Y-STR set is able to differentiate close male relatives in a large pedigree.展开更多
AIM:To identify the pathogenic gene variant in a family with lacrimo-auriculo-dento-digital syndrome[LADD(MIM 149730)]showing congenital lacrimal duct dysplasia as the main clinical manifestation and lay the foundatio...AIM:To identify the pathogenic gene variant in a family with lacrimo-auriculo-dento-digital syndrome[LADD(MIM 149730)]showing congenital lacrimal duct dysplasia as the main clinical manifestation and lay the foundation for future research on the pathogenic gene.METHODS:Ophthalmological examinations,including slit-lamp biomicroscopy and lacrimal duct probing,and computed tomography dacryocystography(CT-DCG)were performed for all participants.The family pedigree was drawn,genetic features were analyzed,and the genomic DNA of the subjects was extracted.Pathogenic genes were screened via whole exome sequencing(WES)and confirmed using Sanger sequencing.RESULTS:Six patients belonged to this three-generation family,and their clinical manifestations included congenital nasolacrimal duct obstruction,congenital absence of lacrimal puncta and canaliculi,lacrimal fistulae,and limb deformities.This pattern indicates autosomal dominant inheritance.Diagnosis was based on the clinical characteristics of LADD syndrome,which presented in all the patients in this family.A novel frameshif t mutation in the FGF10 gene(NM_004465.1),c.234dup C(p.Trp79Leus*15),was identified in all patients via WES.The variant was confirmed by Sanger sequencing and classified as a“pathogenic mutation”according to the American College of Medical Genetics and Genomics(ACMG)variant interpretation guidelines.CONCLUSION:A novel frameshift mutation in the FGF10 gene is found in all patients.This finding helps this family with LADD syndrome receiving a more accurate clinical diagnosis and genetic counseling by extending the mutation range of the FGF10 gene.展开更多
Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to ...Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to the central nervous system.Point mutations in the human prion protein gene can cause prion diseases such as Creutzfeldt-Jakob and Gerstmann's syndrome.To understand the mechanism of mutation-induced prion protein aggregation,the mutants in an aqueous solution are studied by molecular dynamics simulations,including the wild type,V180I,H187R and a double point mutation which is associated with CJD and GSS.After running simulations for 500 ns,the results show that these three mutations have different effects on the kinetic properties of PrP.The high fluctuations around the N-terminal residues of helix 2 in the V180I variant lead to a decrease in hydrogen bonding on helix 2,while an increase in the number of hydrogen bonds between the folded regions promotes the generation ofβ-sheet.Meanwhile,partial deletion of salt bridges in the H187R and double mutants allows the sub-structural domains of the prion protein to separate,which would accelerate the conversion from PrPC to PrPSc.A similar trend is observed in both SASA and Rg for all three mutations,indicating that the conformational space is reduced and the structure is compact.展开更多
A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structure...A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structures of the wild-type and mutant Arg273His (R273H) were simulated with the same thermodynamic and environmental parameters. The obtained results demonstrate that the induced Arg273His mutation has a considerable effect on the p53→DNA close contact interaction and changes the picture of hydrogen formation. The Arg273His mutation, in some cases, destroys the existing native hydrogen bond, but, in other cases, forms a strong p53→DNA hydrogen bond, which is not proper for the native protein. The MD simulation results illustrate some molecular mechanism of the conformational changes of the Arg273His key amino acid residue in the p53→DNA binding domain, which might be important for the understanding of the physiological functioning of the p53 protein and the origin of cancer.展开更多
The K-Ras protein plays a key role in the signal transduction cascade. Certain mutations in K-Ras lead to a permanent “on” state which results in tumorigenesis due to failed interaction with the GTPase activating pr...The K-Ras protein plays a key role in the signal transduction cascade. Certain mutations in K-Ras lead to a permanent “on” state which results in tumorigenesis due to failed interaction with the GTPase activating protein (GAP). In this study, we examined the mutations E31N, D33N and D38N of K-Ras coupled and decoupled to wildtype GAP-334 and mutation K935N of GAP-334 coupled and decoupled to wildtype K-Ras, to illustrate the potential mechanism by which these mutants affect the interaction between the two proteins. We identify Tyr32 in the Ras Switch I region as a critical residue that acts as a gate to the GTP binding site and which needs to be “open” during Ras coupling with GAP to allow for insertion of GAP residue Arg789. This residue plays a vital role in stabilizing the transition state during GTP hydrolysis. The different mutations studied herein caused a reduced binding affinity, and the fluctuation of the Tyr32 side chain might hinder the insertion of Arg789. This may in turn be the cause of decreased GTP hydrolysis, and permanent “on” state of K-Ras, observed for these mutants.展开更多
文摘Objective To discuss clinical diagnosis and treatment of multiple endocrine neoplasia ( MEN) 2A,and report the mutation of RET proto-oncogene in a pedigree of three patients with MEN 2A. Methods Bilateral adrenalectomy was performed on two of the three
基金ThisprojectwassupportedbythegrantofNationalNaturalFoundationofSciences (No 3 95 70 3 45 )
文摘OBJECTIVE: To report the clinical characteristics, biochemical profiles, diagnosis and treatment of one Chinese pedigree with glucocorticoid-remediable aldosteronism (GRA) and to study its molecular mechanism. METHODS: Plasma and urinary aldosterone, cortisol and plasma renin activities were dynamically tested and diagnostic therapy with dexamethasone was undergone in 3 affected subjects. Long-distance PCR as well as DNA sequencing were applied to detect the fusion gene in this pedigree. RESULTS: In this GRA pedigree, there were 4 affected subjects who had hypertension, hypokalemia and low basic and provoked renin activity. Three patients were given dexamethasone treatment, and had a significant decrease in plasma aldosterone concentrations (PACs) (from 192 +/- 9 ng/L to 87 +/- 7ng/L, P
基金This work was financially supported by the Innovative Research Team of the Ministry of Education of China(Grant No.IRT1136)the National Natural Science Foundation of China(Grant No.31672383)the National Swine Industry and Technology System of China(Grant No.nycytx-009).
文摘The mutation rate used in the previous analyses of pig evolution and demographics was cursory and hence invited potential bias in inferring evolutionary history.Herein,we estimated the de novo mutation rate of pigs as 3.6×10-9 per base per generation using high-quality whole-genome sequencing data from nine individuals in a three-generation pedigree through stringent filtering and validation.Using this mutation rate,we re-investigated the evolutionary history of pigs.The estimated divergence time of~10 kiloyears ago(KYA)between European wild and domesticated pigs was consistent with the domestication time of European pigs based on archaeological evidence.However,other divergence events inferred here were not as ancient as previously described.Our estimates suggest that Sus speciation occurred~1.36 million years ago(MYA);European wild pigs split from Asian wild pigs only~219 KYA;and south and north Chinese wild pigs split~25 KYA.Meanwhile,our results showed that the most recent divergence event between Chinese wild and domesticated pigs occurred in the Hetao Plain,northern China,approximately 20 KYA,supporting the possibly independent domestication in northern China along the middle Yellow River.We also found that the maximum effective population size of pigs was~6 times larger than estimated before.An archaic migration from other Sus species originating~2 MYA to European pigs was detected during western colonization of pigs,which may affect the accuracy of previous demographic inference.Our de novo mutation rate estimation and its consequences for demographic history inference reasonably provide a new vision regarding the evolutionary history of pigs.
文摘Objective To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy(HCM)focusing on the cardiac troponic C gene TNNC1 c.G175C mutation.Methods All family members of a Chinese pedigree with hypertrophic cardiomyopathy admitted in Third People’s Hospital of Qingdao
文摘To report a new screening method for mitochondrial DNA 1555A→G mutation and the results of genotype analysis in 19 maternal inherited deafness pedigrees. Method Five hundred and forty-six non-syndromic neuro-sensory hearing loss patients were tested for 1555A→G mutation using a new compact testing kit, which allows clear distinction between wild type and 1555 A→G mutated mtDNAs. Results Nineteen subjects among the 546 patients (3.48%) were found to carry mtDNA A1555G mutation. The results were confirmed by sequencing in an ABI 3100 Avant sequencer. Conclusions Maternal inherited deafness families are a frequently seen in outpatient group. The detection of mtDNA 1555 A→G mutation with a low cost, ready to use detection kit is needed and suitable in China for large scale screening and preventive testing before usage of aminoglycoside antibiotics.
基金Supported by the National Natural Science Foundation of China(61333010,61134007and 21276078)“Shu Guang”project of Shanghai Municipal Education Commission,the Research Talents Startup Foundation of Jiangsu University(15JDG139)China Postdoctoral Science Foundation(2016M591783)
文摘Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-differentiable or explicit mathematical descriptions do not exist. Recently, evolutionary algorithms are gaining popularity for DOPs as they can be used as robust alternatives when the deterministic techniques are invalid. In this article, a technology named ranking-based mutation operator(RMO) is presented to enhance the previous differential evolution(DE) algorithms to solve DOPs using control vector parameterization. In the RMO, better individuals have higher probabilities to produce offspring, which is helpful for the performance enhancement of DE algorithms. Three DE-RMO algorithms are designed by incorporating the RMO. The three DE-RMO algorithms and their three original DE algorithms are applied to solve four constrained DOPs from the literature. Our simulation results indicate that DE-RMO algorithms exhibit better performance than previous non-ranking DE algorithms and other four evolutionary algorithms.
文摘A dynamic genetic algorithms based on numeric encoding is proposed and its application in system identification is discussed. Simulation shows that the introduction of both numeric encoding and dynamic mutation can effectively improve the accuracy and speed of searching for the optimum. It also show that the improved Genetic algorithm can identify time delay and parameters of the plant at the same time and converge to globle optimization.
基金the Natural Science Foundation of Hunan Province, No.2010JJ5045
文摘The present study examined 58 members of a Kallmann syndrome family and investigated whether there are fibroblast growth factor receptor 1 (FGFR1) gene mutations in this family. Genomic DNA from the proband and family members was subjected to PCR to amplify 18 exons of FGFR1, and the amplified products were sequenced to identify potential mutations. MRI of the olfactory bulb region was performed on suspected subjects. The patient and his father were diagnosed with Kallmann syndrome. A polymorphic site was found at 39542, with the proband and his parents being heterozygous (guanine + cytosine). However, healthy controls and the other members of this family were homozygous for guanine at this position.
基金This work was supported by the National Natural Science Foundation of China[grant number 81401557]This study was funded by ICH-GCP Standardization Construction and Innovation of GCP System[grant number 2018ZX09201018-020].
文摘Short tandem repeats on the Y chromosome(Y-STRs),characterized by paternal inheritance,are valuable in forensic practice.Notably,the potential application of Y-STRs in pedigrees should be drawn upon,especially in China’s surname-concentrated natural villages.The study focused on 50 Y-STRs,including 13 rapidly mutating(RM)Y-STRs that largely constitute the current Y-STR commercial kits,and determined the differences in these Y-STRs between branches in a large pedigree and the discriminatory power of these haplotypes in different units for male relatives.As indicated in the results,14 inconsistencies were observed at 9 Y-STRs between 10 father-son pairs.In addition,these 50 Y-STR haplotypes discriminated 10 out of 47 father-son pairs,106 of 148 cousin pairs,70 of 119 uncle-nephew pairs,17 of 39 brother pairs,and 14 out of 33 grandfather-grandson pairs in a large pedigree.The RM Y-STR set is able to differentiate close male relatives in a large pedigree.
基金Supported by the Capital’s Funds for Health Improvement and Research (No.CFH.2020-2Z-5132)。
文摘AIM:To identify the pathogenic gene variant in a family with lacrimo-auriculo-dento-digital syndrome[LADD(MIM 149730)]showing congenital lacrimal duct dysplasia as the main clinical manifestation and lay the foundation for future research on the pathogenic gene.METHODS:Ophthalmological examinations,including slit-lamp biomicroscopy and lacrimal duct probing,and computed tomography dacryocystography(CT-DCG)were performed for all participants.The family pedigree was drawn,genetic features were analyzed,and the genomic DNA of the subjects was extracted.Pathogenic genes were screened via whole exome sequencing(WES)and confirmed using Sanger sequencing.RESULTS:Six patients belonged to this three-generation family,and their clinical manifestations included congenital nasolacrimal duct obstruction,congenital absence of lacrimal puncta and canaliculi,lacrimal fistulae,and limb deformities.This pattern indicates autosomal dominant inheritance.Diagnosis was based on the clinical characteristics of LADD syndrome,which presented in all the patients in this family.A novel frameshif t mutation in the FGF10 gene(NM_004465.1),c.234dup C(p.Trp79Leus*15),was identified in all patients via WES.The variant was confirmed by Sanger sequencing and classified as a“pathogenic mutation”according to the American College of Medical Genetics and Genomics(ACMG)variant interpretation guidelines.CONCLUSION:A novel frameshift mutation in the FGF10 gene is found in all patients.This finding helps this family with LADD syndrome receiving a more accurate clinical diagnosis and genetic counseling by extending the mutation range of the FGF10 gene.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52073128,12164002,and 11964012)the Foundation of Educational Committee of Jiangxi Province of China (Grant No.GJJ211112)the Fund for Distinguished Young Scholars of Jiangxi Science&Technology Normal University (Grant No.2015QNBJRC002)。
文摘Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to the central nervous system.Point mutations in the human prion protein gene can cause prion diseases such as Creutzfeldt-Jakob and Gerstmann's syndrome.To understand the mechanism of mutation-induced prion protein aggregation,the mutants in an aqueous solution are studied by molecular dynamics simulations,including the wild type,V180I,H187R and a double point mutation which is associated with CJD and GSS.After running simulations for 500 ns,the results show that these three mutations have different effects on the kinetic properties of PrP.The high fluctuations around the N-terminal residues of helix 2 in the V180I variant lead to a decrease in hydrogen bonding on helix 2,while an increase in the number of hydrogen bonds between the folded regions promotes the generation ofβ-sheet.Meanwhile,partial deletion of salt bridges in the H187R and double mutants allows the sub-structural domains of the prion protein to separate,which would accelerate the conversion from PrPC to PrPSc.A similar trend is observed in both SASA and Rg for all three mutations,indicating that the conformational space is reduced and the structure is compact.
文摘A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structures of the wild-type and mutant Arg273His (R273H) were simulated with the same thermodynamic and environmental parameters. The obtained results demonstrate that the induced Arg273His mutation has a considerable effect on the p53→DNA close contact interaction and changes the picture of hydrogen formation. The Arg273His mutation, in some cases, destroys the existing native hydrogen bond, but, in other cases, forms a strong p53→DNA hydrogen bond, which is not proper for the native protein. The MD simulation results illustrate some molecular mechanism of the conformational changes of the Arg273His key amino acid residue in the p53→DNA binding domain, which might be important for the understanding of the physiological functioning of the p53 protein and the origin of cancer.
基金The Faculty of Science at the University of Gothenburg is gratefully acknowledged for financial support
文摘The K-Ras protein plays a key role in the signal transduction cascade. Certain mutations in K-Ras lead to a permanent “on” state which results in tumorigenesis due to failed interaction with the GTPase activating protein (GAP). In this study, we examined the mutations E31N, D33N and D38N of K-Ras coupled and decoupled to wildtype GAP-334 and mutation K935N of GAP-334 coupled and decoupled to wildtype K-Ras, to illustrate the potential mechanism by which these mutants affect the interaction between the two proteins. We identify Tyr32 in the Ras Switch I region as a critical residue that acts as a gate to the GTP binding site and which needs to be “open” during Ras coupling with GAP to allow for insertion of GAP residue Arg789. This residue plays a vital role in stabilizing the transition state during GTP hydrolysis. The different mutations studied herein caused a reduced binding affinity, and the fluctuation of the Tyr32 side chain might hinder the insertion of Arg789. This may in turn be the cause of decreased GTP hydrolysis, and permanent “on” state of K-Ras, observed for these mutants.